摘要：The essence of rheumatoid arthritis (RA) pathogenesis is inflammation, modification of immune system and cell damage. 5'-nucleotidase (5'-NT) and adenosine deaminase (ADA) have a significant role in the process of inflammation-caused tissue damage. The aim of the paper is to define 5'-nucleotidase and adenosine deaminase activity in serum of patients with rheumatoid arthritis treated with Methotrexate and patients with rheumatoid arthritis who have not been treated with Methotrexate, as well as to determine correlation between the enzymes and disease activity. The research included 160 patients suffering from rheumatoid arthritis, 60 of which have not been treated with Methotrexate (age 56,8; 68,3% female) and 100 patients treated with Methotrexate (age 59,8; 88% female), as well as 60 healthy controls (age 58,8; 66,6% female). Patients suffering from chronic inflammatory diseases, chronic respiratory, cardiac and kidney insufficiency, severe acute diseases and other diseases which might modify inflammatory response were not included in the research. There was no statistically significant difference in 5'-NT values among groups. ADA values were significantly different in all tested groups. Post Hoc analysis (Dunnett T3 test) showed that ADA activity in RA groups were significantly higher as compared to control group (p<0.001), and that ADA in RA group with MTX was significantly smaller as compared to RA group without MTX (p<0.001). There is not significant correlation between the disease activity and activities of tested enzymes. We concluded that adenosine deaminase activity was increased in patients with rheumatoid arthritis, as well as that the application of Methotrexate led to the decrease of this enzyme in the serum of patients with rheumatoid arthritis. Activity of 5'-nucleotidase is not increased in patients with rheumatoid arthritis and did not depend on Methotrexate treatment. Serum adenosine deaminase and 5'-nucleotidase were not good indicators of rheumatoid arthritis activity. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 31060]
